[Clam-devel] Re: gsoc project - real time synthesizer for a woodwind instrument

Greg Kellum greg.kellum at gmail.com
Tue Jun 3 09:59:09 PDT 2008

Hi Yushen,

> (1) The format of the score
> But anything I edited by hand results in segmentation fault
> because the program mistook multiple lines for one frame.

I can vaguely remember having the same problem, and *** I think *** it
was because the parser was sensitive to whether the line ended with
carriage return line feeds or just line feeds.  (Don't blame me for
this;  I'm just using a standard C++ function for reading lines. ;-)
Try editing the score file with a text editor that lets you set what
is used for line breaks, and experiment to see what works...

> (2) the synthesized frames
> Why is the even lines in the text score are skipped in the synthesis?
> The assumption for "one frame" in the score is SR = 44100Hz and HOPSIZE =
> 256 Samples.
> Is that correct?

Wow, I had never noticed that before!  I have no idea why that is happening...

> (3) ( to both Pau and Greg )
> Besides the problems above, the sound is not good

Well, another reason it probably doesn't sound good is that I'm not
using the residual.  For what I was synthesizing -- ebow notes -- the
residual wasn't important, and it was taking a lot of processor power.
 So, I disabled it.  But for what you are synthesizing, the residual
is very important.

If you look at the file ContinuousExcitationSynthesizer, you'll notice
that the function responsible for synthesizing the spectral frames is
using the class SinusoidalSynthesis.  You should be able to change
this to use SMSSynthesis instead pretty easily, and then, the residual
part will be synthesized as well.


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